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[Author] Soon LEE(10hit)

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  • Predicting Political Orientation of News Articles Based on User Behavior Analysis in Social Network Open Access

    Jun-Gil KIM  Kyung-Soon LEE  

     
    PAPER

      Vol:
    E97-D No:4
      Page(s):
    685-693

    News articles usually represent a biased viewpoint on contentious issues, potentially causing social problems. To mitigate this media bias, we propose a novel framework for predicting orientation of a news article by analyzing social user behaviors in Twitter. Highly active users tend to have consistent behavior patterns in social network by retweeting behavior among users with the same viewpoints for contentious issues. The bias ratio of highly active users is measured to predict orientation of users. Then political orientation of a news article is predicted based on the bias ratio of users, mutual retweeting and opinion analysis of tweet documents. The analysis of user behavior shows that users with the value of 1 in bias ratio are 88.82%. It indicates that most of users have distinctive orientation. Our prediction method based on orientation of users achieved 88.6% performance in accuracy. Experimental results show significant improvements over the SVM classification. These results show that proposed detection method is effective in social network.

  • Global Stabilization of a Class of Feedforward Nonlinear Systems with Unknown Growth Rate and Input Delay by Output Feedback

    Ho-Lim CHOI  Jin-Soo KIM  Jae-Seung YOUN  Kwon Soon LEE  

     
    LETTER-Systems and Control

      Vol:
    E92-A No:11
      Page(s):
    2932-2935

    We consider a problem of global asymptotic stabilization of a class of feedforward nonlinear systems that have the unknown linear growth rate and unknown input delay. The proposed output feedback controller employs a dynamic gain which is tuned adaptively by monitoring the output value. As a result, a priori knowledge on the linear growth rate and delay size are not required in controller design, which is a clear benefit over the existing results.

  • Efficient Analysis of Electromagnetic Coupling Problem via Aperture into Parallel Plate Waveguide and Its Application to Electromagnetic Pulse (EMP) Coupling

    Young-Soon LEE  Jong-Kyu KIM  Young-Ki CHO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E85-C No:1
      Page(s):
    212-218

    A numerically efficient analysis method, combining closed-form Green's functions with the method of moments (MoM) of the mixed potential integral equation (MPIE) approach, is considered for the electromagnetic coupling problem through an aperture into a parallel plate waveguide (PPW), as a complementary problem to the microstrip patch structure problem, and then applied to the electromagnetic pulse (EMP) penetration problem. Some discussion on the advantages of the present method is also presented from the perspective of computational electromagnetics.

  • Kalman-Filter Based Estimation of Electric Load Composition with Non-ideal Transformer Modeling

    Soon LEE  Seung-Mook BAEK  Jung-Wook PARK  Young-Hyun MOON  

     
    PAPER-Numerical Analysis and Optimization

      Vol:
    E90-A No:12
      Page(s):
    2877-2883

    This paper presents a study to estimate the composition of an electric load, i.e. to determine the amount of each load class by the direct measurements of the total electric current waveform from instrument reading. Kalman filter algorithm is applied to estimate the electric load composition on a consumer side of a distributed power system. The electric load supplied from the different voltage level by using a non-ideal delta-wye transformer is also studied with consideration of the practical environment for a distributed power system.

  • Efficient Computation of MoM Matrix Elements in Analysis of General Microstrip Structure

    Young-Soon LEE  Eui-Joong KIM  Young-Ki CHO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E85-C No:12
      Page(s):
    2109-2116

    An efficient method for calculating impedance matrix elements is proposed for analysis of microstrip structures with an arbitrary substrate thickness. Closed-form Green's functions are derived by applying the GPOF method to the remaining function after the extraction of the contributions of the surface wave pole, source dipole itself, and quasi-static (i.e.real images) from a spectral domain Green's function. When closed-form Green's functions are used in conjunction with rooftop-pulse subsectional basis functions and the razor testing function in an MoM with an MPIE formulation, the integrals appearing in the calculation procedure of the diagonal matrix elements are of two types. The first is x0n [e^(-jk0(x02 + y02 +a2)1/2)/(x02 + y02 +a2)1/2)]dx0dy0 (where n=0, 1) for the contribution of both the source dipole itself or real images where a=0 and complex images where a=complex constant, while the other is x0n H0(2)(kρp (x02 + y02)1/2)dx0dy0 for the contribution of the surface wave pole where kρp is a real pole due to the surface wave. Adopting a polar coordinate for the integral for both cases of n=0 and n=1 and performing analytical integrations for n=1 with respect to the variable x0 for both types not only removes the singularities but also drastically reduces the evaluation time for the numerical integration. In addition, the above numerical efficiency is also retained for the off-diagonal elements. To validate the proposed method, several numerical examples are presented.

  • Diffraction of a Gaussian Beam Wave by Finite Periodic Slots in a Parallel-Plate Waveguide

    Jong-Ig LEE  Cheol-Hoon LEE  Young-Soon LEE  Young-Ki CHO  

     
    PAPER-Antenna and Propagation

      Vol:
    E84-B No:1
      Page(s):
    95-99

    The diffraction problem of a Gaussian beam by finite number of periodic slots in a parallel-plate waveguide filled with a homogeneous dielectric is considered. The integro-differential equation for the unknown equivalent surface magnetic current density over the slots is derived and solved by the method of moments (piecewise sinusoidal Galerkin method). From some theoretical results for the angular diffraction pattern, the present geometry is observed to simulate well the previous rectangular groove geometry from the viewpoint of scattering behaviour. In addition, two types (resonance and non-resonance types) of Bragg blazing phenomena are discussed. Simultaneous Bragg and off-Bragg blazing is also demonstrated.

  • Efficient Patch Merging for Atlas Construction in 3DoF+ Video Coding

    Hyun-Ho KIM  Sung-Gyun LIM  Gwangsoon LEE  Jun Young JEONG  Jae-Gon KIM  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2020/12/14
      Vol:
    E104-D No:3
      Page(s):
    477-480

    The emerging three degree of freedom plus (3DoF+) video provides more interactive and deep immersive visual experience. 3DoF+ video introduces motion parallax to 360 video providing omnidirectional view with limited changes of the view position. A large set of views are required to support such 3DoF+ visual experience, hence it is essential to compress a tremendous amount of 3DoF+ video. Recently, MPEG is developing a standard for efficient coding of 3DoF+ video that consists of multiple videos, and its test model named Test Model for Immersive Video (TMIV). In the TMIV, the redundancy between the input source views is removed as much as possible by selecting one or several basic views and predicting the remaining views from the basic views. Each unpredicted region is cropped to a bounding box called patch, and then a large number of patches are packed into atlases together with the selected basic views. As a result, multiple source views are converted into one or more atlas sequences to be compressed. In this letter, we present an improved clustering method using patch merging in the atlas construction in the TMIV. The proposed method achieves significant BD-rate reduction in terms of various end-to-end evaluation metrics in the experiment, and was adopted in TMIV6.0.

  • Novel PNP BJT Structure to Improve Matching Characteristics for Analog and Mixed Signal Integrated Circuit Applications

    Seon-Man HWANG  Yi-Jung JUNG  Hyuk-Min KWON  Jae-Hyung JANG  Ho-Young KWAK  Sung-Kyu KWON  Seung-Yong SUNG  Jong-Kwan SHIN  Yi-Sun CHUNG  Da-Soon LEE  Hi-Deok LEE  

     
    PAPER

      Vol:
    E96-C No:5
      Page(s):
    663-668

    In this paper, we suggest a novel pnp BJT structure to improve the matching characteristics of the bipolar junction transistor (BJT) which is fabricated using standard CMOS process. In the case of electrical characteristics, the collector current density Jc of the proposed structure (T2) is a little greater than the conventional structure (T1), which contributes to the greater current gain β of the proposed structure than the conventional structure. Although the matching characteristics of the collector current density of the proposed structure is almost similar to the conventional structure, that of the current gain of the proposed structure is better than the conventional structure about 14.81% due to the better matching characteristics of the base current density of the proposed structure about 59.34%. Therefore, the proposed BJT structure is desirable for high performance analog/digital mixed signal application.

  • Wider Depth Dynamic Range Using Occupancy Map Correction for Immersive Video Coding

    Sung-Gyun LIM  Dong-Ha KIM  Kwan-Jung OH  Gwangsoon LEE  Jun Young JEONG  Jae-Gon KIM  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2023/02/10
      Vol:
    E106-D No:5
      Page(s):
    1102-1105

    The MPEG Immersive Video (MIV) standard for immersive video coding provides users with an immersive sense of 6 degrees of freedom (6DoF) of view position and orientation by efficiently compressing multiview video acquired from different positions in a limited 3D space. In the MIV reference software called Test Model for Immersive Video (TMIV), the number of pixels to be compressed and transmitted is reduced by removing inter-view redundancy. Therefore, the occupancy information that indicates whether each pixel is valid or invalid must also be transmitted to the decoder for viewport rendering. The occupancy information is embedded in a geometry atlas and transmitted to the decoder side. At this time, to prevent occupancy errors that may occur during the compression of the geometry atlas, a guard band is set in the depth dynamic range. Reducing this guard band can improve the rendering quality by allowing a wider dynamic range for depth representation. Therefore, in this paper, based on the analysis of occupancy error of the current TMIV, two methods of occupancy error correction which allow depth dynamic range extension in the case of computer-generated (CG) sequences are presented. The experimental results show that the proposed method gives an average 2.2% BD-rate bit saving for CG compared to the existing TMIV.

  • Effects of Fluorine Implantation on 1/f Noise, Hot Carrier and NBTI Reliability of MOSFETs

    Jae-Hyung JANG  Hyuk-Min KWON  Ho-Young KWAK  Sung-Kyu KWON  Seon-Man HWANG  Jong-Kwan SHIN  Seung-Yong SUNG  Yi-Sun CHUNG  Da-Soon LEE  Hi-Deok LEE  

     
    PAPER

      Vol:
    E96-C No:5
      Page(s):
    624-629

    The effects of fluorine implantation on flicker noise and reliability of NMOSFET and PMOSFETs were concurrently investigated. The flicker noise of an NMOSFET was decreased about 66% by fluorine implantation, and that of a PMOSET was decreased about 76%. As indicated by the results, fluorine implantation is one of the methods that can be used to improve the noise characteristics of MOSFET devices. However, hot-carrier degradation was enhanced by fluorine implantation in NMOSFETs, which can be related to the difference of molecular binding within the gate oxide. On the contrary, in case of PMOSFETs, NBTI life time was increased by fluorine implantation. Therefore, concurrent investigation of hot-carrier and NBTI reliability and flicker noise is necessary in developing MOSFETs for analog/digital mixed signal applications.